Module: ActiveRecord::ConnectionHandling

Defined in:

lib/brick/extensions.rb

Overview

Get info on all relations during first database connection

Instance Method Summary

• #_brick_establish_connection ⇒ Object
• #_brick_reflect_tables ⇒ Object

  This is done separately so that during testing it can be called right after a migration in order to make sure everything is good.

• #establish_connection(*args) ⇒ Object
• #retrieve_schema_and_tables(sql = nil, is_postgres = nil, schema = nil) ⇒ Object

Instance Method Details

#_brick_establish_connection ⇒ Object

# File 'lib/brick/extensions.rb', line 1308

alias _brick_establish_connection establish_connection

#_brick_reflect_tables ⇒ Object

This is done separately so that during testing it can be called right after a migration in order to make sure everything is good.

# File 'lib/brick/extensions.rb', line 1320

def _brick_reflect_tables
  initializer_loaded = false
  if (relations = ::Brick.relations).empty?
    # If there's schema things configured then we only expect our initializer to be named exactly this
    if File.exist?(brick_initializer = Rails.root.join('config/initializers/brick.rb'))
      initializer_loaded = load brick_initializer
    end
    # Load the initializer for the Apartment gem a little early so that if .excluded_models and
    # .default_schema are specified then we can work with non-tenanted models more appropriately
    apartment = Object.const_defined?('Apartment')
    if apartment && File.exist?(apartment_initializer = Rails.root.join('config/initializers/apartment.rb'))
      load apartment_initializer
      apartment_excluded = Apartment.excluded_models
    end
    # Only for Postgres  (Doesn't work in sqlite3 or MySQL)
    # puts ActiveRecord::Base.execute_sql("SELECT current_setting('SEARCH_PATH')").to_a.inspect

    is_postgres = nil
    case ActiveRecord::Base.connection.adapter_name
    when 'PostgreSQL'
      is_postgres = true
      db_schemas = ActiveRecord::Base.execute_sql('SELECT DISTINCT table_schema FROM INFORMATION_SCHEMA.tables;')
      ::Brick.db_schemas = db_schemas.each_with_object({}) do |row, s|
        row = row.is_a?(String) ? row : row['table_schema']
        # Remove any system schemas
        s[row] = nil unless ['information_schema', 'pg_catalog'].include?(row)
      end
      if (is_multitenant = (multitenancy = ::Brick.config.schema_behavior[:multitenant]) &&
         (sta = multitenancy[:schema_to_analyse]) != 'public') &&
         ::Brick.db_schemas.include?(sta)
        ::Brick.default_schema = schema = sta
        ActiveRecord::Base.execute_sql("SET SEARCH_PATH = ?", schema)
      end
    when 'Mysql2'
      ::Brick.default_schema = schema = ActiveRecord::Base.connection.current_database
    when 'SQLite'
      # %%% Retrieve internal ActiveRecord table names like this:
      # ActiveRecord::Base.internal_metadata_table_name, ActiveRecord::Base.schema_migrations_table_name
      sql = "SELECT m.name AS relation_name, UPPER(m.type) AS table_type,
        p.name AS column_name, p.type AS data_type,
        CASE p.pk WHEN 1 THEN 'PRIMARY KEY' END AS const
      FROM sqlite_master AS m
        INNER JOIN pragma_table_info(m.name) AS p
      WHERE m.name NOT IN (?, ?)
      ORDER BY m.name, p.cid"
    else
      puts "Unfamiliar with connection adapter #{ActiveRecord::Base.connection.adapter_name}"
    end

    ::Brick.db_schemas ||= {}

    if ActiveRecord::Base.connection.adapter_name == 'PostgreSQL'
      if (possible_schema = ::Brick.config.schema_behavior&.[](:multitenant)&.[](:schema_to_analyse))
        if ::Brick.db_schemas.key?(possible_schema)
          ::Brick.default_schema = schema = possible_schema
          ActiveRecord::Base.execute_sql("SET SEARCH_PATH = ?", schema)
        else
          puts "*** In the brick.rb initializer the line \"::Brick.schema_behavior = ...\" refers to a schema called \"#{possible_schema}\".  This schema does not exist. ***"
        end
      end
    end

    # %%% Retrieve internal ActiveRecord table names like this:
    # ActiveRecord::Base.internal_metadata_table_name, ActiveRecord::Base.schema_migrations_table_name
    # For if it's not SQLite -- so this is the Postgres and MySQL version
    measures = []
    case ActiveRecord::Base.connection.adapter_name
    when 'PostgreSQL', 'SQLite' # These bring back a hash for each row because the query uses column aliases
      # schema ||= 'public' if ActiveRecord::Base.connection.adapter_name == 'PostgreSQL'
      ActiveRecord::Base.retrieve_schema_and_tables(sql, is_postgres, schema).each do |r|
        # If Apartment gem lists the table as being associated with a non-tenanted model then use whatever it thinks
        # is the default schema, usually 'public'.
        schema_name = if ::Brick.config.schema_behavior[:multitenant]
                        Apartment.default_schema if apartment_excluded&.include?(r['relation_name'].singularize.camelize)
                      elsif ![schema, 'public'].include?(r['schema'])
                        r['schema']
                      end
        relation_name = schema_name ? "#{schema_name}.#{r['relation_name']}" : r['relation_name']
        relation = relations[relation_name]
        relation[:isView] = true if r['table_type'] == 'VIEW'
        relation[:description] = r['table_description'] if r['table_description']
        col_name = r['column_name']
        key = case r['const']
              when 'PRIMARY KEY'
                relation[:pkey][r['key'] || relation_name] ||= []
              when 'UNIQUE'
                relation[:ukeys][r['key'] || "#{relation_name}.#{col_name}"] ||= []
                # key = (relation[:ukeys] = Hash.new { |h, k| h[k] = [] }) if key.is_a?(Array)
                # key[r['key']]
              end
        key << col_name if key
        cols = relation[:cols] # relation.fetch(:cols) { relation[:cols] = [] }
        cols[col_name] = [r['data_type'], r['max_length'], measures&.include?(col_name), r['is_nullable'] == 'NO']
        # puts "KEY! #{r['relation_name']}.#{col_name} #{r['key']} #{r['const']}" if r['key']
      end
    else # MySQL2 acts a little differently, bringing back an array for each row
      ActiveRecord::Base.retrieve_schema_and_tables(sql).each do |r|
        relation = relations[(relation_name = r[1])] # here relation represents a table or view from the database
        relation[:isView] = true if r[2] == 'VIEW' # table_type
        col_name = r[3]
        key = case r[6] # constraint type
              when 'PRIMARY KEY'
                # key
                relation[:pkey][r[7] || relation_name] ||= []
              when 'UNIQUE'
                relation[:ukeys][r[7] || "#{relation_name}.#{col_name}"] ||= []
                # key = (relation[:ukeys] = Hash.new { |h, k| h[k] = [] }) if key.is_a?(Array)
                # key[r['key']]
              end
        key << col_name if key
        cols = relation[:cols] # relation.fetch(:cols) { relation[:cols] = [] }
        # 'data_type', 'max_length'
        cols[col_name] = [r[4], r[5], measures&.include?(col_name)]
        # puts "KEY! #{r['relation_name']}.#{col_name} #{r['key']} #{r['const']}" if r['key']
      end
    end

    # # Add unique OIDs
    # if ActiveRecord::Base.connection.adapter_name == 'PostgreSQL'
    #   ActiveRecord::Base.execute_sql(
    #     "SELECT c.oid, n.nspname, c.relname
    #     FROM pg_catalog.pg_namespace AS n
    #       INNER JOIN pg_catalog.pg_class AS c ON n.oid = c.relnamespace
    #     WHERE c.relkind IN ('r', 'v')"
    #   ).each do |r|
    #     next if ['pg_catalog', 'information_schema', ''].include?(r['nspname']) ||
    #       ['ar_internal_metadata', 'schema_migrations'].include?(r['relname'])
    #     relation = relations.fetch(r['relname'], nil)
    #     if relation
    #       (relation[:oid] ||= {})[r['nspname']] = r['oid']
    #     else
    #       puts "Where is #{r['nspname']} #{r['relname']} ?"
    #     end
    #   end
    # end
    # schema = ::Brick.default_schema # Reset back for this next round of fun
    case ActiveRecord::Base.connection.adapter_name
    when 'PostgreSQL', 'Mysql2'
      sql = "SELECT kcu1.CONSTRAINT_SCHEMA, kcu1.TABLE_NAME, kcu1.COLUMN_NAME,
                kcu2.CONSTRAINT_SCHEMA AS primary_schema, kcu2.TABLE_NAME AS primary_table, kcu1.CONSTRAINT_NAME AS CONSTRAINT_SCHEMA_FK
        FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS AS rc
          INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS kcu1
            ON kcu1.CONSTRAINT_CATALOG = rc.CONSTRAINT_CATALOG
            AND kcu1.CONSTRAINT_SCHEMA = rc.CONSTRAINT_SCHEMA
            AND kcu1.CONSTRAINT_NAME = rc.CONSTRAINT_NAME
          INNER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS kcu2
            ON kcu2.CONSTRAINT_CATALOG = rc.UNIQUE_CONSTRAINT_CATALOG
            AND kcu2.CONSTRAINT_SCHEMA = rc.UNIQUE_CONSTRAINT_SCHEMA
            AND kcu2.CONSTRAINT_NAME = rc.UNIQUE_CONSTRAINT_NAME#{"
            AND kcu2.TABLE_NAME = kcu1.REFERENCED_TABLE_NAME
            AND kcu2.COLUMN_NAME = kcu1.REFERENCED_COLUMN_NAME" unless is_postgres }
            AND kcu2.ORDINAL_POSITION = kcu1.ORDINAL_POSITION#{"
        WHERE kcu1.CONSTRAINT_SCHEMA = COALESCE(current_setting('SEARCH_PATH'), 'public')" if is_postgres && schema }"
        # AND kcu2.TABLE_NAME = ?;", Apartment::Tenant.current, table_name
    when 'SQLite'
      sql = "SELECT m.name, fkl.\"from\", fkl.\"table\", m.name || '_' || fkl.\"from\" AS constraint_name
      FROM sqlite_master m
        INNER JOIN pragma_foreign_key_list(m.name) fkl ON m.type = 'table'
      ORDER BY m.name, fkl.seq"
    else
    end
    if sql
      # ::Brick.default_schema ||= schema ||= 'public' if ActiveRecord::Base.connection.adapter_name == 'PostgreSQL'
      ActiveRecord::Base.execute_sql(sql).each do |fk|
        fk = fk.values unless fk.is_a?(Array)
        # Multitenancy makes things a little more general overall, except for non-tenanted tables
        if apartment_excluded&.include?(fk[1].singularize.camelize)
          fk[0] = Apartment.default_schema
        elsif is_postgres && (fk[0] == 'public' || (is_multitenant && fk[0] == schema)) ||
              !is_postgres && ['mysql', 'performance_schema', 'sys'].exclude?(fk[0])
          fk[0] = nil
        end
        if apartment_excluded&.include?(fk[4].singularize.camelize)
          fk[3] = Apartment.default_schema
        elsif is_postgres && (fk[3] == 'public' || (is_multitenant && fk[3] == schema)) ||
              !is_postgres && ['mysql', 'performance_schema', 'sys'].exclude?(fk[3])
          fk[3] = nil
        end
        ::Brick._add_bt_and_hm(fk, relations)
      end
    end
  end

  tables = []
  views = []
  relations.each do |k, v|
    name_parts = k.split('.')
    idx = 1
    name_parts = name_parts.map do |x|
      ((idx += 1) < name_parts.length ? x.singularize : x).camelize
    end
    if v.key?(:isView)
      views
    else
      name_parts.shift if apartment && name_parts.length > 1 && name_parts.first == Apartment.default_schema
      tables
    end << name_parts.join('::')
  end
  unless tables.empty?
    puts "\nClasses that can be built from tables:"
    tables.sort.each { |x| puts x }
  end
  unless views.empty?
    puts "\nClasses that can be built from views:"
    views.sort.each { |x| puts x }
  end

  ::Brick.load_additional_references if initializer_loaded
end

#establish_connection(*args) ⇒ Object

# File 'lib/brick/extensions.rb', line 1309

def establish_connection(*args)
  conn = _brick_establish_connection(*args)
  begin
    _brick_reflect_tables
  rescue ActiveRecord::NoDatabaseError
  end
  conn
end

#retrieve_schema_and_tables(sql = nil, is_postgres = nil, schema = nil) ⇒ Object

# File 'lib/brick/extensions.rb', line 1530

def retrieve_schema_and_tables(sql = nil, is_postgres = nil, schema = nil)
  sql ||= "SELECT t.table_schema AS \"schema\", t.table_name AS relation_name, t.table_type,#{"
    pg_catalog.obj_description(
      ('\"' || t.table_schema || '\".\"' || t.table_name || '\"')::regclass, 'pg_class'
    ) AS table_description," if is_postgres}
    c.column_name, c.data_type,
    COALESCE(c.character_maximum_length, c.numeric_precision) AS max_length,
    tc.constraint_type AS const, kcu.constraint_name AS \"key\",
    c.is_nullable
  FROM INFORMATION_SCHEMA.tables AS t
    LEFT OUTER JOIN INFORMATION_SCHEMA.columns AS c ON t.table_schema = c.table_schema
      AND t.table_name = c.table_name
    LEFT OUTER JOIN INFORMATION_SCHEMA.KEY_COLUMN_USAGE AS kcu ON
      -- ON kcu.CONSTRAINT_CATALOG = t.table_catalog AND
      kcu.CONSTRAINT_SCHEMA = c.table_schema
      AND kcu.TABLE_NAME = c.table_name
      AND kcu.position_in_unique_constraint IS NULL
      AND kcu.ordinal_position = c.ordinal_position
    LEFT OUTER JOIN INFORMATION_SCHEMA.table_constraints AS tc
      ON kcu.CONSTRAINT_SCHEMA = tc.CONSTRAINT_SCHEMA
      AND kcu.TABLE_NAME = tc.TABLE_NAME
      AND kcu.CONSTRAINT_NAME = tc.constraint_name
  WHERE t.table_schema #{is_postgres ?
      "NOT IN ('information_schema', 'pg_catalog')"
      :
      "= '#{ActiveRecord::Base.connection.current_database.tr("'", "''")}'"}#{"
    AND t.table_schema = COALESCE(current_setting('SEARCH_PATH'), 'public')" if is_postgres && schema }
--          AND t.table_type IN ('VIEW') -- 'BASE TABLE', 'FOREIGN TABLE'
    AND t.table_name NOT IN ('pg_stat_statements', ?, ?)
  ORDER BY 1, t.table_type DESC, 2, c.ordinal_position"
  ar_smtn = if ActiveRecord::Base.respond_to?(:schema_migrations_table_name)
              ActiveRecord::Base.schema_migrations_table_name
            else
              'schema_migrations'
            end
  ar_imtn = ActiveRecord.version >= ::Gem::Version.new('5.0') ? ActiveRecord::Base.internal_metadata_table_name : ''
  ActiveRecord::Base.execute_sql(sql, ar_smtn, ar_imtn)
end